Solar thermal collector

The invention concerns flat pack solar thermal collectors and related systems, kits and methods.

The generation of renewable heat is a significant global challenge, given that heat accounts for approximately 50% of total energy end use. As society shifts towards clean technologies to meet its energy needs, the demand for low cost renewable heat technologies continues to grow.

Examples of traditional solar thermal collectors that are commercially available include flat plate and evacuated tube collectors, which employ a material that absorbs solar radiation and convert it to heat. This heat energy is then transferred to a fluid and used to meet the customers' energy needs. However, these traditional solar thermal collectors have several drawbacks:

Therefore, there is a need to address the decarbonisation of heat, with technologies that are relatively easily installed, light-weight, durable, easy to transport, resistant to damage from frost, cheap and simple to assemble, such that people living in both developed and developing countries may straightforwardly implement the technology.

It is an aim of example embodiments of the present invention to address one or more problems associated with traditional solar thermal collectors, whether identified herein, or otherwise.

According to a first aspect, there is provided a solar thermal collector adapted to be assembled from a flat pack configuration. The solar thermal collector comprises a conduit configured to carry fluid and to absorb radiation, a base above which the conduit is mounted and a plurality of panels configured to interconnect with the base to produce a housing for the conduit.

In one example, one or more of the panels is translucent. In one example, one or more of the panels is transparent. In one example, one or more of the panels is semi-transparent. In one example, one or more of the panels is partially transparent. In one example, one or more of the panels is mirrored. In one example, one or more of the panels is semi-silvered such that in use the reflective surface is internal of the housing.

In one example, the panels narrow from where they connect to the base. In one example, the panels progressively narrow from where they connect to the base. In one example, the panels are tapered.

In one example, one or more of the panels is triangular. In one example, one or more of the panels is substantially triangular.

In one example, all the panels are triangular. In one example, all the panels are substantially triangular.

In one example, the panels are interchangeable. In one example, the panels are identical with one another.

In one example, each of the panels rest on a first housing support plate. In one example, a second housing support plate caps the first housing support plate to clasp the panels in place. In one example the second housing support plate is transparent, semi-transparent, partially transparent or translucent. In one example, the first housing support plate and the second housing support plate are transparent, semi-transparent, partially transparent or translucent. In one example, the second housing support plate comprises clear UV stabilised polycarbonate. In one example, the first housing support plate and the second housing support plate comprise clear UV stabilised polycarbonate.

In one example, a face of the base that is in contact with the surface on which the solar thermal collector is placed is flat. In one example, a face of the base that is in contact with the surface on which the solar thermal collector is placed is pliable.

In one example, the base is generally square in shape.

In one example, the conduit is supported by a column which is attached to the base.

In one example, the column is located in the centre of the base. In one example, the column is offset from the centre of the base.

In one example, the column comprises a plurality of plates. In one example, one of more of the plurality of plates is triangular.

In one example, the column is a frame. In one example, the column is a cage structure.

In one example, one or more of the plurality of plates comprises fastening points for attaching the plurality of plates to each other. In one example, one or more of the plurality of plates comprises slots for connecting the plates to form the column.

In one example, the plates comprise guides for supporting the conduit. In one example, the plates comprise ridged edges. In one example, the plates comprise adhesive strips to adhere the conduit to the guides.

In one example, the ridged edges are downwardly sloping. In one example, the ridges edges are inwardly sloping.

In one example, the base comprises one or more base attachment formations. In one example, the one or more base attachment formations are aligned with each other. In one example, the one or more base attachment formations are aligned with the centre of the base. In one example, the one or more base attachment formations are displaced from the centre of the base.

In one example, the column comprises column attachment formations. In one example, the column attachment formations are complementary to the base attachment formations.

In one example, the conduit is flexible.

In one example, the conduit has a collapsible cross-section.

In one example, the conduit is boustrophedon or a coil. In one example, the conduit is helical. In one example, the face of the base facing the conduit is mirrored.

In one example, the face facing the conduit of at least one panel is mirrored.

In one example, the housing encloses the conduit. In one example, the housing hermetically seals the conduit from its surroundings.

In one example, the base comprises a plurality of sections. In one example, one or more of the plurality of sections comprises an interlocking mechanism. In one example, the interlocking mechanism is a magnetic mechanism.

In one example, the solar thermal collector further comprises an inlet port to supply fluid for circulation by the conduit and an outlet port to collect water that has been circulated by the conduit.

In one example, the conduit comprises a plastics material. In one example, the conduit comprises silicone.

In one example, the conduit comprises a plastic sleeve. In one example, the conduit comprises a plastic tube.

In one example, the base comprises aluminium. In one example, the base comprises a plastics material.

In one example, the panels comprise a plastics material. In one example, the panels comprise an acrylic material. In one example, the panels comprise PMMA. In one example, the panels comprise solar glass.

According to a second aspect, there is provided a system comprising a plurality of solar thermal collectors.

According to third aspect, there is provided a kit comprising a conduit configured to carry fluid and to absorb radiation, a base above which the conduit is mounted and a plurality of panels configured to interconnect with the base to produce a housing for the conduit for constructing the solar thermal collector.

According to a fourth aspect, there is provided a method of constructing a solar thermal collector, comprising assembling the kit.

shows a baseof a solar thermal collector according to an example embodiment. The baseshown inis square. The basecomprises aluminium, so as to be durable yet relatively light-weight. Consequently, the basecan be easily transported and assembled at an installation site. The basemay include one or more base attachment formations,,to which a column can be attached. For example,shows an base attachment formationat the centre of the baseand two smaller base attachment formations,aligned in one direction but each equidistantly displaced in another from the central base attachment formation.

shows a columnattached to the baseof the solar thermal collector by means of the base attachment formations,,. The columnincludes column attachment formations (not shown) of complementary form or shape to the base attachment formations,,on the base, in order that the columncan be fixed to the basewithout need for tools. The columnofis shown as comprising four right angled triangular plates, where the edge of each triangular plate opposite the hypotenuse meets in the centre of the base.

Sections of the right-angled triangular plates comprising the columnhave been cut out in. Cutting out these sections from the triangular plates that form the columnreduces the overall weight of solar thermal collector making it cheaper to transport, as well as allowing the solar thermal collector to be positioned on the roofs of buildings unable, for example, to support the greater weight of traditional solar thermal collectors.

The columncomprises guidesto support the conduit, the conduit being explained in more detail with reference tobelow. For example,shows the columnto comprise guidesin the form of ridged edges for helping to support and secure the conduit in place without the need for specialized tools. The guidescomprise downwardly and inwardly sloping surfaces, so that the conduit rests on them and against an inwardly arranged part of the column. In this way, the weight of the conduit helps to keep it in place in in the guides.

also shows a first housing support platefor supporting a housing, which is described in relation to, of the solar thermal collector. The first housing support plate shown inis has a square cross section and a square opening through which the top of the columnprotrudes. The geometry of the column, prevents the first housing support plate from sliding down the column. The outwardly facing faces of the first housing support plateslope inwards and upwards to provide surfaces for supporting the housing.

The conduitis shown in. The conduitofis a tube for carrying fluid.shows the conduitas a coil. The conduitcomprises a plastics material, for instance, silicone, resulting in a light-weight and cheaply manufactured structure. The conduitis flexible, allowing the coil shape to be formed, and allowing engagement with the guides. The conduithas a compressible cross-section, so that it is easily folded and packaged and can be incorporated in a flat pack.

Due to a combination of seasonal variation and time of day, the solar angle will natural vary throughout its operation. Having a circular cross-section means that the conduitis able to passively track the sun as the sun moves across the sky through a wide range of solar angles. Therefore, the solar thermal collector may be positioned without a great deal of accuracy without affecting its performance. A flat plate solar thermal collector, on the contrary, needs to be positioned facing the equator and at the correct tilt to minimise losses due to variation in solar angle.

Furthermore, the properties of flexibility and/or compressibility also result in improved resistance to damage caused by the freezing of the liquid in the conduit. For example, if the conduitwere made of metal and was carrying water, the water freezing, and consequently expanding, may rupture the conduit. Therefore, typical solar thermal collectors need to operate with glycol/antifreeze fluid to reduce the risk of fluid freezing in the conduit, adding cost and complexity to the system.

In addition to carrying a fluid, the conduitabsorbs solar radiation. This absorbed energy elevates the wall temperature of the conduit, which can be actively recovered by circulating a cooler fluid through it. At the bottom of the collector is an inlet port (not shown) into which cold water is delivered, for example by a pump. As the cold water makes its way to the top of the conduit, heat is transferred from the conduit wall to the fluid, yielding warm water at the top, which may be accessed via an outlet port.

includes the housingof the solar thermal collector. The housinghouses the conduit, being formed of a plurality of panels which interconnect with the base. Each of the plurality of panels rests on a face of the first housing support platedescribed in. The inwardly and upwardly sloping faces of the first housing support plate each provides a surface on which each of the plurality of panels can rest. A second housing support plate, which is complementary in shape to the first housing support, caps the first housing support plate. By capping the first housing support plate, the second housing support plateclasps the panels in place without the need for specialised tools to secure the housing. The second housing support platepreferably comprises a transparent material so that radiation is not prevented from being incident on the conduitby the second housing support plate.

The panels are transparent, so that radiation can transmit through the panels and elevate the wall temperature of the conduitas described. By supporting the conduiton the column, the surface area of the conduiton which radiation transmitted through each of the panels is incident is increased compared with a conduit laid flat on the base. Consequently, the efficiency of the solar thermal collector is improved compared with a solar thermal collector in which a conduit is flat, without the need for more than one conduit.

The panels are made of a lightweight material, such as an acrylic. Again, use of a plastics material results in the solar thermal collector being light-weight and, thus, easily transportable and suitable for installation on edifices that may not be strong enough to support the weight of a traditional solar thermal panel. Moreover, compared with traditional solar thermal collectors, which use glass, the solar thermal collector of the present application is less susceptible to damage during transport to the installation site and thereafter

The panels shown inare substantially triangular, resulting in the housing, in combination with the base, having the shape of truncated square-based pyramid. The housingmay comprise, alternatively, triangular panels, such that the pyramid is not truncated.